Honest Testing Results for Magnesium Bisglycinate
Why This Post Exists
Most brands wave a pretty Certificate of Analysis (COA) and call it a day. We run three separate lab gauntlets—then publish every number. This is the full data-dump, cost sheet, and methodology so you can verify (or rip apart) our work. At the end of the day, this deep dive is here so that you can trust that what you're putting into your body is actually helping you. Not making expensive pee.
| Test | What It Proves | Cost / Batch |
|---|---|---|
| Elemental Mg (ICP-MS) | How much actual magnesium is present | $192.15 |
| Identity (Bisglycinate vs Oxide) | How much of that Mg is the gentle bisglycinate form | $425 |
| Heavy Metals + Microbials | Safety & legality—lead, arsenic, nasties, etc. | ~$200 |
Total QA bill: $800+ per batch. (Yes, it hurts. No, we’re not cutting corners.)
1. Total Elemental Magnesium
COA Claim: 20 – 22 %
Our ICP-MS Result: 21.9 % (Link here)
What it tells you
Magnesium bisglycinate is a three-piece suit: one Mg atom bonded to two glycines. By weight it’s only ~20 %. Measuring elemental Mg answers, “Am I actually getting 200 mg of magnesium per capsule—or just filler?”
Why it’s not the whole picture
An assay can’t see how that Mg is bonded. Cheap magnesium oxide looks identical with this test. Without an identity test, brands can spike elemental Mg with oxide, hit the Mg % target, and brag about “high potency.”
Elemental Magnesium Test Cost Breakdown
This leads us to...
2. Magnesium Bisglycinate Identity
Method used: ¹H Nuclear Magnetic Resonance (¹H NMR) via Purity-IQ’s Molecular Diagnostic Test Method PIQ-MTD-011. (Link here)
- Limit of Detection (LOD): 0.003 mg
- Limit of Quantification (LOQ): 0.0351 mg
- Full spectrum and peak integrations archived for peer review.
| Lot # / Sample Label | Supplier’s Purity Claim | NMR-Verified Bisglycinate % (±SD) | What It Really Means |
|---|---|---|---|
| GMFH24010 (“Magnesium Glycinate 20 %”) | "Fortified" magnesium bisglycinate | 85.27 % ± 6.93 % | Roughly 1 in 7 molecules remained as unreacted oxide or other forms |
See how this compares to the other raw materials we tested in this article here.
Identity Test Cost Breakdown
Takeaways
- “Trust but verify” is dead; just verify.
- “100 % pure” ≠ 100 % pure. Even reputable suppliers leave ~25 % of the batch as magnesium oxide or by-products.
- Positive ID, partial purity. The spectrum on page 2 of the COA shows the characteristic bisglycinate peaks, confirming the molecule is present—but not exclusively.
- Why we still use NMR. It’s the only technique sensitive enough to fingerprint the exact bonding environment—FT-IR and simple titration miss this nuance.
Limitations
No USP-standardized assay exists—labs use slightly different fingerprints. We log every parameter so peers can replicate.
3. Heavy Metals & Microbial Screen
Quick facts (Lot #10427): Lab Results Here
- Lead: 0.09 ppm
- Arsenic: < 0.01 ppm
- Cadmium: < 0.001 ppm
- Mercury: < 0.005 ppm
- Total bugs (yeast, mold, bacteria): < 10 CFU/g; nasties like E. coli and Salmonella were a no-show.
That’s miles inside every serious safety limit. In other words, completely ordinary for a well-made supplement—exactly what you should expect, not a mic-drop moment.
So why publish it?
Because too many brands treat a basic “pass” like it’s radical transparency, flashing a pretty PDF while quietly living closer to the edges—often running lead levels three-to-five times higher than ours (still legal, just not something they brag about). We’d rather show you the boring numbers than hide behind buzzwords.
Bottom line: Results this clean are table stakes. The real transparency is hitting them every batch and letting you see the raw material test results whenever you want. Anything less is just marketing karaoke.
Masquerading Transparency—Four Common Half-Steps
- Certificate of Composition: A recipe typed by the manufacturer—no lab data. Could be Harry Potter fan-fic.
- Supplier-Only COA: Raw material vendors test themselves. No third-party referee means the fox guards the henhouse.
- “Magnesium % = Purity” Sleight-of-hand: Brands flaunt a 14-21 % magnesium result and imply full bisglycinate purity. (Now you know why that’s bunk.)
- Bumper-Sticker Certifications (NSF, cGMP, etc.) They're a helpful baseline, but the documents stay behind a velvet rope. We post ours—batch after batch.
So What?
- Customers: #tapthecap of your Arrow Magnesium Bisglycinate to access these results on every batch. We won't write a blog article explaining each batch. But you know that you're taking Mg bisglycinate.
- Retail Buyers: You get a one-of-a-kind, transparent magnesium supplement on your shelf. This has the opportunity to educate customers like never before.
- Scientists & Health Nerds: Feel free to scrutinize our PDFs, run your own stats, or email us to talk more.
Final Word
Good supplements shouldn’t require faith—just facts.
If another brand can’t show:
- Elemental Mg numbers and
- A bona-fide bisglycinate identity and
- Full heavy-metal/microbial panels
…then you’re gambling. We’ll keep picking up the $800-per-batch tab so you don’t have to.
Still curious? Email us with your toughest question. We answer every one—even the spicy ones.